1. Field of the Invention
The present invention relates to a display device that includes an element having a light emitting material sandwiched between electrodes (hereinafter referred to as a “light emitting element”), and to a manufacturing method of the display device. In particular, the invention relates to a display device using a light emitting material that generates EL (Electro Luminescence) (hereinafter also referred to as an “EL material”).
2. Description of the Related Art
An EL material (particularly, an organic EL material) that mainly constitutes an EL element is characterized in that it is sensitive to moisture and degrades easily. Therefore, when an EL display device is manufactured, a technique for reducing the moisture content in the device is required. As its measures, a structure in which a drying agent is provided in an EL display device (an electroluminescence device) and then sealed (for example, Reference 1: Japanese Patent Laid-Open No. 2003-297558).
However, even when such measures are taken, the deterioration of an EL display device can not be fully prevented. In other words, a defect caused by the formation of a dot-shaped non-luminescence region or its enlargement in a pixel (hereinafter “a dark spot”), and a defect in which a non-luminescence region from a periphery of a pixel is enlarged over time (hereinafter, “shrink”) can not be eliminated.